Inside delivery scatter feed stoker



J. B. MARSDEN INSIDE DELIVERY SCATTER FEED STOKER Sept. 27, 1949.

Filed Dec. 29, 1944 2' Sheets- Sheet 1 INlfENTOR. damvfilflnexas/v Sept. 27, 1949.

J. B- MAR'SDEN INSIDE DELIVERY SCATTER FEED STOKER 2 Sheets-Sheet 2 Filed Dec. 29, l944 Patented Sept. 27, 1949 INSIDE DELIVERY SCATTER FEED STOKER John B. Marsden, Erie, Pa., assignor to The Standard Stoker Company, Incorporated, a corporation of Delaware Application December 29, 1944, Serial No. 570,278

1 Claim.

This invention relates to locomotive stokers and particularly to that type of stoker wherein the fuel is delivered to the fire through a conduit which enters the fire box beneath the grate and thence passes upward through the grate and terminates in a delivery opening above the fire.

In this type of stoker, a plurality of communicating conduits extend forwardly from beneath the fuel bin of the tender, terminating in an upturned elbow and riser conduit that passes up through the firebox grate a substantial distance above the grate level. Screw conveying means terminating at the elbow of the conduit system advances fuel through the conduits and forces it through the elbow and up through the riser conduit.

An object of the present invention is to provide a front end construction for a stoker of the type described wherein the fuel will have such a very short and direct passage from the forward end of the conveyor screw to the mouth of the discharge conduit that packing of fuel is minimized permitting the fuel to emerge more freely and in a steadier stream from the mouth of the discharge conduit.

In locomotives equipped with stokers in which the fuel is introduced through a conduit extending through the firebox grate and located within the firebox, there is a loss of efiiciency due to the grate area taken up by the stoking mechanism and consequently the amount of fuel that can be burned, and the blanking off of a substantial portion of the back water leg of the firebox by the stoking mechanism, thereby reducing the steaming capacity of the boiler. This is not a serious objection in large fireboxes, but in smaller fireboxes it becomes more pronounced. It is therefore, another object of the invention to provide a stoker of this general type in which encroachment of the stoker on the grate area and the firebox back water leg is reduced.

A further object of the invention is to provide a novel discharge end for a stoker of the type described including an elbow shaped discharge conduit, pressure fluid distributor head and firing table, that is compact, takes up a minimum amount of space in the firebox and that is readily assembled.

Other objects and advantages of the invention residing in the features of construction, combination of elements, and arrangement of parts, will become apparent from the following description and the accompanying drawings, in which Figure 1 is a fragmentary diagrammatic View of a locomotive and tender with the novel stoker applied thereto and shown in central vertical longitudinal section with parts in elevation;

Figure 2 is a fragmentary plan View of the stoker shown in Figure 1; and

Figure 3 is an enlarged sectional plan view 2 through the fluid pressure distributor head of the stoker.

A conventional type of locomotive and tender is indicated generally by the numerals I0 and l l, respectively. The locomotive Ill includes a cab deck l2, a sloping back water leg l3 having a firing opening I4 above the level of the cab deck l2, 2. firebox l5 and the firebox grate IS. The walls of the boiler including its back water leg l3 which enclose the firebox l5 are, as usual, hollow and are bounded at the bottom by a foundation or mud ring II. The tender II is provided with a fuel bin l8 having an apertured floor l9.

Mounted beneath the apertured floor IQ of the tender and arranged to receive fuel from the fuel bin I8 is the stoker trough 2!], through which the fuel is conveyed by a screw conveyer 46 as shown in Figure 2. The trough 20 is provided at its forward end with a short tubular extension 2| which communicates with a forwardly extending tubular conduit comprising a rearward section 22 universally jointed to the tubular extension 2|, and a forward section 23 loosely telescopically connected with the rearward section 22.

The forward section 23 is universally jointed at its forward end with a horizontal tubular conduit 24 which is supported on the frame 25 of the locomotive and terminates at its forward end beneath the mud ring H. A system of screw conveyors including the screw conveyor 46 in the trough 20, a screw conveyor 26 in the telescopic conduit sections 22, 23, and a screw conveyor 21 in the conduit 24 conveys fuel forwardly through the conduit system. Since the forward end of the screw conveying system is not fixed in a bearing it bears against the walls of the forward end of conduit 24 causing this portion of the conduit to wear more rapidly than other parts. For this reason conduit 24 is preferably made in a number of sections including rear section 28 and vertically split front sections 29 and 39, permitting renewal of the faster wearing parts without replacing the entire conduit. If desired, the conduit 24 may, of course, be made in one piece.

The forward end of conduit 24 communicates with a elbow conduit 3| supported on the locomotive frame 25 and extending upwardly through the firebox grate l6. Since in stoker firing, with a stoker of the type described, fuel is continuously being fed over the fire bed instead 0f intermittently as in hand firing, a shallower and more efficient fire bed can be maintained. It is generally desirable to maintain a fuel bed of approximately 4 to 6 inches deep In the present construction, the upwardly extending ortion of elbow conduit 3| terminates approximately 8 inches above the level of the grate 16 or several inches above the preferred level of the firebed. In larger fireboxes, it is preferable to have the discharge end of the stoker at a greater height above the level of the grate, in order to reduce the pressure of the fuel projecting jets of steam or other fluid. Because of the inwardly sloping back water leg of the conventional type of locomotive,

it is apparent that the higher the discharge mouth of the stoker, the farther. inwardly of the firebox the discharge conduit will extend and consequently occupy a greater'area of thefirebox grate and back water leg. As pointed out before, in a large firebox this is not a serious disadvantage and is preferred in order to reduce the jet pressure necessary to project fuel to the distant areas of the firebox. However, in smaller fireboxes, for which the present invention is particularly adapted, the amount of space that the stoker blanks oii the grate and back water leg, is material to the eificient operation'of the boiler.

Referring to Figure 1, it will be seen that in the present construction, the upper rearward edge of the mouth of the elbow 3| lies in a vertical transverse plane which if extended upwardly intersects the back water leg l3 at a point below the firing opening 14. With the upwardly extending portion of the elbow conduit 3| disposed in such close proximity to the back water leg it, it is apparent that the conduit l3 obstructs a minimum 01 grate area.

The rear wall 32 of the upwardly extending portion of the elbow conduit 3| is indented'as at 33, in which indentation is mounted a. pressure fluid jet head 34. The jet head '34 is secured tothe elbow conduit 3| in any suitable manneryas by bolts passing through the flanges 36 and the rear wall 32 of the upwardly extending portionof conduit 3|. The jet head 34 slopes forwardly from its lower to its upper end so that at its lower end it projects rearwardly of the rear wall 32 and at its upper end projects forwardly of the rear wall 32 into the mouth of the conduit 3|. Fluid, such as steam, is admitted to the. jet head 34 through its bottom by'means of a'plurality'of pipes 31 extending beneath the mud ring I1.

The upper end of the jet head 33 extends above the upper edge of the conduit 3|, as best shown in Figure 1, and is provided in its wedgeshaped front wall with a plurality of jet openings '38, as shown in Figure 3, directed over all parts of the firebox for projecting the coal as it emerges from the conduit 3|. The jet head 34 is'preferably divided into a plurality of compartmentsBQ each connected with a separate pressure fluidpipe 31, so that by means of suitable valves (not shown) in the pipes 37 the pressure fluid in the various compartments 39 may be controlled thereby controlling the amount of fuel, projected over various areas of the firebox.

The jet openings 38, as shown in Figure 1, are inclined from their respective inlet ends to their respective outlet ends in order to gain the proper trajectory for projecting the fuel. Ifdesired' the inclination of the jet openings 38 of any compartment 39 may vary inaccordance with the distance from the jet openings to the wall of the firebox toward which they are directed.

Supported from the upper end of theconduit 31 is a protecting grate 40 substantially U 'shaped in horizontal cross section protecting the sides'and front of the conduit 3i from the heat of the firebox. The protecting grate is spaced "irom' the conduit 3| permitting air to be drawn through this-space from the ash pit 4|. A plurality-of openings 42 in the protecting grateifl'permit the air to be drawn into the firebox by the draft there- 4 in. This circulation of air serves to keep the conduit 3| and the protectinggrate cool.

'A= flange? projecting inwardlyffronrthe upper edge of the protecting grate'40 seats on the upper edge of the conduit 3| and forms a firing table across which the coal emerging from the conduit is;.projected by thepressure fluid blasts issuing from the jetopenings 38 in the jet head 34. Lugs ranged to be received in complementary recesses formed in the table portion 43 of the protect- .inggrate 40. The protecting grate 40 with its table'43 is thus securediagainst any substantial movement in a horizontal plane with respect to the conduit '3 I I claim:

In a locomotive, provided with a firebox having a forwardly and upwardly sloping rear waterleg disposed throughout in a straight flat plane'with a firing opening therein and a'mud ring at its lower end; an elbow shaped fuel feed conduit extending forwardly beneath said mud ringand thence extending'upward'ly through said grate and terminating at its'disc'harge end forward'oi the plane of said rear water legand at approximately the normal level of the firebed, the upwardly extending portion of'said conduit being in such proximity with respect to said rear water leg that its upper rearward edge lies in'a vertical transverse plane intersecting the plane of said rear water leg below the lower edge of said firing opening, said conduit having a recessinits rear wall extending from its upper edge downwardly below the normal level of the fircbed, anda hollow pressure fluid distributor head mounted in said recess and extending above the upper edge ofsaid conduit,- said distributor head having its lower hollow portion adjacent the lowermost end of said recess projecting outwardly of saidconduit and its major upper hollow, portion projecting inwardly of and within said conduit, the inwardly'projecting portion of said hollow distributor head tapering from its upper end adjacent the mouth of said dischargeconduit to its lower end adjacent the bottom of saidrecess, the loweroutwardly projecting portion of said distributor head beinggprovided with downwardly opening pressure fluid admission ports and the upper inwardly projecting portion'of 'said distributor head being-provided witha' plurality of jet apertures directedacross the delivery mouth of said discharge conduit for directing a plura'lity of fluid jets against the fuel emerging from said conduit.

JOHN -B. MARSDEN.

- REFERENCES CITED The. following references are of record in the le of this patent:

UNITED. STATES PATENTS Number Name Date 1,567,083 Roesch, et al Dec. 29, 1925 1,663,636 Lower, et a1 Mar. 27, 1928 1,674,994 Roesch June 26, 1928 1,690,1 6 Hunt Nov. 6,1928 1,718,065 Osborne June 18, 1929 1,773,103 Hunt Aug. 19, 1930 1,932,349 Marcoux 0017.24, 1933 2,033,061 Anderson Mar. 3, 1936 2,092,403 -Myers Sept. 7, 1937 2,105,457 1 Ichter J an. 11, 1938 2,121,313 Binney June 2 1938 2,177,794 Turner 'Oct.' 31,- 1939 

